Keyboard for musical instruments

ABSTRACT

A keyboard structure especially for musical instruments and the like, in which an upwardly opening metal channel is supported on a leaf spring at the back to permit vertical movement of the channel while a downwardly opening plastic cap member is mounted on top of the metallic channel and projects from the front end of the channel. A chassis is provided supporting the leaf spring and also having upward and downward stop arrangements for limiting the vertical movement of the key and also includes a lateral guide for the key.

[ June 12, 1973 United States Patent [191 Slaats et al.

[ KEYBOARD FOR MUSICAL INSTRUMENTS 2,253,782 8/1941 Hammond et al. 84/423 2,844,065 7/1958 Corwin 84/433 X 3,248,992 5/1966 Wood et al. 84/436 [75] Inventors: Mathew A. Slants; James E.

Blessinger, both of Jasper, lnd.

Assignee: Jasper Electronics Manufacturing Primary Examiner-Richard B. Wilkinson Corporation, Jasper, lnd. Assistant Examiner-John F. Gonzales Oct 28 1970 Attorney-Melvin A. Crosby Appl. No.: 84,588

[22] Filed:

[57} ABSTRACT A keyboard structure especially for musical instru- '-n--'-neneon-u-u-"nu-vnun-unn-nunig4gig 58] g 0 3 4 channel is supported on a leaf spring at the back to permit vertical movement of the channel while a downwardly opening plastic cap member is mounted on top References Cited UNITED STATES PATENTS of the metallic channel and projects from the front end of the channel. A chassis is provided supporting the leaf spring and also having upward and downward stop ar- 84/434 84/ 2 rangements for limiting the vertical movement of the 84/423 key and also includes a lateral guide for the key. 84/434 X 84/423 f n u "u e m m mm .mm m m n ME E mk mu HELSM 13311. 76664 99999 11111 Ill/l 483 11 6 Claims, 5 Drawing Figures PAIENIEU SIEH'I. If 2 INVENTORb MATHEW A. sLAn'rs BY JAMES E. BLESSWGER pmmm M I 2 ma Sim 2 BF 2 FIG-2 34 56 38 W52 44 I I I 36 L 46 :2 22 -1 24 FIG-3 FIG-4 INVENTORS MATHEW R, SLMTS BY JAMES E. BLESSINGER WWW KEYBOARD FOR MUSICAL INSTRUMENTS The present invention relates to keyboard structures and is particularly concerned with a keyboard structure for a musical instrument such as an organ or piano.

Keyboards are, of course, well known and have heretofore taken many different forms. In most pianos the key is pivotally supported and is forced downwardly at the back by the weight of the action which the key actuates when it is depressed in the front. In electric organs, however, there is no action which the key actuates but, rather, a switching arrangement is actuated by the key which controls the sounds issued by the organ. In such a case, it is usually necessary to spring the key toward rest position, while providing upper and lower stop arrangements for halting the key at opposite ends of its travel.

Instrument keys which are returned under the force of a spring have heretofore been devised in various manners and included are arrangements wherein the key is biased toward rest position by a leaf spring.

With the advent of electric organs, in particular, keys have been made of a combination of metal and plastic, the metal often being in the form of a T-shaped or an inverted U-shape and with the plastic taking the form of a cap member mounted thereon. Such keys are satisfactory with regard to wear and appearance but lack the rigidity against twisting and bending that is characteristic of, for example, a wooden piano key according to the prior art. The metal and plastic instrument keys do, however, offer the advantages of lightness and low cost to manufacture and ease of assembly and repair as well as having a pleasing appearance and a pleasant touch.

With the foregoing in mind, a primary objective of the present invention is the provision of an instrument key and supporting structure thereon of the nature referred to which is improved in operation and ease of manufacture over what has been available heretofore.

Another object of the present invention is the provi- 4 sion of an instrument key, especially for electric organs, in which a plastic cap is mounted on a metal support member with the cap and support member being so arranged as to provide for great strength and rigidity against bending and twisting while still remaining quite light and inexpensive.

A still further object of the present invention is the provision of an instrument key and a supporting structure therefor in which adjustment of the key is readily possible in order to place it in exactly the right position to bring it into conformity with adjacent keys and to insure proper movement thereof.

Still another object of the present invention is the provision of an instrument key and supporting structure therefor in which the key can be adjusted in the fore and aft direction as well as laterally and in the up and down direction, thereby providing for complete adjustability of the key in any direction necessary to place it in the proper position.

Still a further object of the present invention is the provision of an instrument key, especially for an electronic organ or the like, in which the bias on the key can readily be adjusted so as to adapt the touch of the key to the preference of the player.

The foregoing objects of the present invention as well as still other objects and advantages thereof will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIG. 1 is a somewhat schematic perspective view showing a key and support structure therefor according to the present invention;

FIG. 2 is a side view of the key and supporting structure, partly in section;

FIG. 3 is a plan section indicated by line Ill-III on FIG. 2, showing a novel feature in respect of the guide at the front end of the key;

FIG. 4 is a transverse section showing an alternate method of connecting the cap of the key to the support channel; and

FIG. 5 is a fragmentary longitudinal sectional view at the rear end of the key, showing the provision of an adjustment for the fore and aft position of the key.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhat more in detail, in FIGS. 1 and 2 there is shown a stationary support member 10 of an instrument having a front member 12 upstanding therefrom. Mounted on stationary member 10 is a chassis generally indicated at 14 and forming a part of the present invention. Chassis 14 comprises a generally rectangular wooden front rail 16 and a metal chassis plate 18 mounted on top of the rail 16 and extending rearwardly therefrom and at the rear end being turned up at an angle to form laterally extending rib 20.

Attached to the underneath side of chassis member 18 toward the rear end, in any suitable manner, is an angular transversely extending support bracket 22 which is fastened to stationary member 10 as by screws 24. Member 18 in the transverse direction preferably spans a unit of 12 keys, making up an octave of the keyboard. This forms a convenient size in which member 18 can be made and forms a convenient size for machining and assembly work.

It will be understood, therefore, that in looking at, for example, FIG. 1, while only a single key is shown, specifically, either the key B or the key E, the usual member 18 will actually support a row of 12 keys consisting of seven white keys and five black keys. Where less than a full octave of keys is encountered at either end of the keyboard, a special member 18 with the requisite number of keys is provided. In such a case, the end key may be of a special type.

According to the present invention, each key is formed of a metal channel 26, steel for example, which in cross section is U-shaped and which, at the rear end of the key, has a projecting tab 28 turned up substantially at right angles to the length of channel 26. Tab 28 may be integral with channel 26, or it may be separate therefrom and attached to the channel, as by a screw, as will be described hereinafter. Tab 28 preferably has struck up portions 29 to engage the sides of a leaf spring element. Tab 28 has a washer 30 attached thereto by means of screw 32 and between the washer 30 and tab 28 is clamped the upper end of a leaf spring element 34, which is preferably in the form of a finger extending upwardly from an elongated strip.

The lower end of the spring element lies along the rear side of the upturned rib 20 at the rear end of chassis member 18. A spring retainer plate 36 is disposed on the opposite side of the lower end of the leaf spring from upturned rib 20 and is held in place by rivet means 38. Individual spring retainers 36 can be provided for individual spring leafs 34 but it is advantageous for spring retainer 36 and the leaf spring member to extend the full length of member 18 and to be secured to the upturned rib 20 by rivets distributed along the length of member 18.

The aforementioned channel 26, as will best be seen in FIG. 2, is the same width from end to end, but-deepens toward the front end of the key and is adapted to receive thereover toward the front of the channel a plastic key cap 40 which may be of any suitable color but which is usually white. The key cap is preferably cemented to the channel but may be secured thereto in any other suitable manner. Cementing the cap in place assists in making the key structure stiff against bending. An alternate method of connecting the cap to the channel is shown in FIG. 4 wherein screw 42, toward the rear end of the key extends through the cap and is threaded through the bottom wall of support channel 26.

Fixed to the bottom of channel 26 and extending downwardly therefrom, somewhat at an angle so as to be substantially tangential to a circle drawn about the point of flexure of spring 34, is a threaded stud 44 which extends through an aperture 46 in member 18. On the underside of member 18 stud 44 carries a felt washer 48 and an adjustable stop nut 50. Aperture 46, as will be seen in FIG. 1, is keyhole shaped with the large end of the keyhole being large enough to accommodate the felt washer 48 and nut 50, while the rear end of the aperture is only large enough to accommodate stud 44.

Because of the described configuration of the aperture 46, the removing of screw 32 will permit the key readily to be removed from the support chassis merely by moving the key forwardly until nut 50 aligns with the large part of the aperture, and then lifting the key upwardly. Similarly, the key can be replaced by reversing the aforementioned steps.

Mounted on top of stationary member 18 toward the front is a strip 52 of foamed elastomeric material which serves as a downstop for the key. It will be apparent that the strip 52, and the combination of stud 44, felt washer 48 and nut 50 provide for down and up stops for the key and with at least the up stop thereof being adjustable so that the key can be stopped in exactly the right upper position.

Forwardly of strip 52 is a guide pin 54 which has a cylindrical lower end driven into rail 16 and a somewhat flattened, or oval, upper end. The upper end of guide pin 54 will be seen in plan section in FIG. 3. The pin 54 extends through an elongated aperture 56 formed in the bottom of rail 26 and through an elongated guide bushing 58 mounted on the bottom wall of channel 26.

The described arrangement of the guide pin 54 and the bushing 58, which engages the sides of the guide pin, guides the key in its up and down motion. At the same time, due to the reduced lateral dimension of the upper end of pin 54, the pin can readily be bent laterally in one direction or the other, thereby precisely to adjust the position of the key in the lateral direction relative to adjacent keys. This feature is quite important in respect of providing a keyboard having the best possible appearance and action.

The guide bushing 58, which is also oval when relaxed, is mounted in the guide channel between the side walls thereof and has two knob-like projections 59 receivable in holes 61 in the key channel. The bushing is held with the sides parallel. The pin 54 can then be rotated to get the best engagement of the pin with the sides of the guide bushing and thereby control the lateral play of the key.

The channel 26 and the plastic cap 40, when placed together, and as will be seen in FIG. 4, form a hollow box-like channel which is extremely rigid against bending and twisting. The features of stiffness against bending and twisting of the key is quite important to the proper feel and operation thereof and is distinctly better with a key constructed according to the present invention that one in which the channel 26 opens downwardly or when it is formed to a T or an L shape. At the same time, no lightness is lost in arriving at the rigid beam-like nature of the key according to the present invention.

Fore and aft adjustability of the key can be provided for as shown in FIG. 5 by mounting within the metal channel of the key indicated at 26a an L-shaped bracket 60 having a slot 62 therein through which a screw 64 passes which connects the L-shaped bracket to the key channel. The rear end of L-shaped bracket 60 is turned up and is secured to the respective leaf spring 34a for the key. The slot could, of course, be provided in the key channel and the screw threaded into the bracket.

It will readily be evident, upon reference to FIG. 5, that the key of which channel 26a forms a part can readily be adjusted somewhat in the fore and aft direction merely be loosening screw 64 and positioning the key in the desired position and then again tightening screw 64. The modification of FIG. 5 provides an additional adjustment whereby all of the keys of a keyboard can easily be precisely aligned in the fore and aft direction.

In either of the modifications illustrated and described, the upturned tab at the rear end of the key to which the upper end of the respective key biasing leaf spring is attached, can be bent in the fore and aft direction with a simple tool, thereby to adjust the bias on the key. Thus, if a player wishes a relatively stiff action, the tabs 28, 60 are bent in one direction and if the player wishes a softer, or freer, action the tabs 28, 60 are bent in the opposite direction.

A keyboard constructed according to the present invention is thus readily adjustable to meet individual specification, and which are often encountered especially with performing players as, for example, professional type players.

Each key of the keyboard is easily removeable and replaceable and is adjustable in all directions while the keyboard structure is, at the same time, inexpensive.

For use with pianos, the key would include an arrangement for actuating the respective hammer in the piano action while for use with an organ, the key would include an arrangement for actuating a respective valve or switch structure.

Modifications can be made within the scope of the appended claims.

What is claimed is:

l. A keyboard structure, especially for a musical instrument, and including a key, said key comprising an upwardly opening channel shaped metallic supporting member having a bottom wall and upstanding legs and extending forwardly from the rear of the key and a downwardly opening channel shaped cap member having a top wall and dependent legs and extending rearwardly from the front of the key, a portion of the lengths of said members being coextensive and means fixedly interconnecting said members, the top wall of said cap member resting on the upper edges of the legs of said supporting member and the legs of said cap member closely embracing the legs of said supporting member, a tab upstanding from the rear end of the supporting member, a stationary chassis member having an upstanding flange disposed beneath said tab, a leaf spring engaging both said flange and tab in face to face engagement therewith and fixed thereto, said flange terminating at the top near the bottom of said tab whereby a short length only of said leaf spring is exposed to form a pivot region for said key, a stud dependent from said supporting member, an aperture in said chassis member through which said stud extends, an abutment element on said stud beneath said chassis member forming an up stop for the key, and sound deadening means interposed between the upper side of said abutment element and the underside of said chassis member.

2. A keyboard structure according to claim 1 in which said leaf spring is detachably connected to said supporting member, and said aperture includes an enlarged region disposed in the forward direction from the normal location of said stud and larger in diameter than said abutment element whereby upon detaching said supporting member from said leaf spring the said key can be shifted in the forward direction and removed from the chassis member by drawing the abutment element upwardly through said enlarged region.

3. A keyboard structure according to claim 1 in which said bottom wall of said supporting member is provided with a longitudinally elongate guide bushing near the front, said guide bushing being disposed on the upper side of the bottom wall and between the legs of the supporting member, and a stationary guide pin upstanding from the chassis member and extending into said elongate guide bushing and slidably engaging the laterally opposite sides of said guide bushing.

4. A keyboard structure according to claim 3 in which said guide pin in at least the region engaged by said guide bushing has a smaller dimension in the lateral direction than in the fore and aft direction so as to be readily bendable for precise lateral location of the front end of said key and is rotatable to adjust the side play of the key.

5. A keyboard structure according to claim 3 which includes sound deadening stop means mounted on the upper side of said chassis member and engageable by the bottom of said key in depressed position thereof.

6. A keyboard structure according to claim 3 in which said guide bushing has projections on the outside of the side walls engageable with holes formed in the said legs of said supporting member to hold the guide bushing in the supporting member, said guide bushing being oval and wider across the narrow dimension than the lateral distance between the legs of said supporting member when relaxed and having the side walls compressed into parallel relation when mounted in said supporting member between the said legs thereof.

it t 

1. A keyboard structure, especially for a musical instrument, and including a key, said key comprising an upwardly opening channel shaped metallic supporting member having a bottom wall and upstanding legs and extending forwardly from the rear of the key and a downwardly opening channel shaped cap member having a top wall and dependent legs and extending rearwardly from the front of the key, a portion of the lengths of said members being coextensive and means fixedly interconnecting said members, the top wall of said cap member resting on the upper edges of the legs of said supporting member and the legs of said cap member closely embracing the legs of said supporting member, a tab upstanding from the rear end of the supporting member, a stationary chassis member having an upstanding flange disposed beneath said tab, a leaf spring engaging both said flange and tab in face to face engagement therewith and fixed thereto, said flange terminating at the top near the bottom of said tab whereby a short length only of said leaf spring is exposed to form a pivot region for said key, a stud dependent from said supporting member, an aperture in said chassis member through which said stud extends, an abutment element on said stud beneath said chassis member forming an up stop for the key, and sound deadening means interposed between the upper side of said abutment element and the underside of said chassis member.
 2. A keyboard structure according to claim 1 in which said leaf spring is detachably connected to said supporting member, and said aperture includes an enlarged region disposed in the forward direction from the normal location of sAid stud and larger in diameter than said abutment element whereby upon detaching said supporting member from said leaf spring the said key can be shifted in the forward direction and removed from the chassis member by drawing the abutment element upwardly through said enlarged region.
 3. A keyboard structure according to claim 1 in which said bottom wall of said supporting member is provided with a longitudinally elongate guide bushing near the front, said guide bushing being disposed on the upper side of the bottom wall and between the legs of the supporting member, and a stationary guide pin upstanding from the chassis member and extending into said elongate guide bushing and slidably engaging the laterally opposite sides of said guide bushing.
 4. A keyboard structure according to claim 3 in which said guide pin in at least the region engaged by said guide bushing has a smaller dimension in the lateral direction than in the fore and aft direction so as to be readily bendable for precise lateral location of the front end of said key and is rotatable to adjust the side play of the key.
 5. A keyboard structure according to claim 3 which includes sound deadening stop means mounted on the upper side of said chassis member and engageable by the bottom of said key in depressed position thereof.
 6. A keyboard structure according to claim 3 in which said guide bushing has projections on the outside of the side walls engageable with holes formed in the said legs of said supporting member to hold the guide bushing in the supporting member, said guide bushing being oval and wider across the narrow dimension than the lateral distance between the legs of said supporting member when relaxed and having the side walls compressed into parallel relation when mounted in said supporting member between the said legs thereof. 